The embodiments herein relate generally to subterranean formation operations and, more particularly, to forming conductive arch channels in subterranean formation fractures.
Hydrocarbon producing wells (e.g., oil producing wells, gas producing wells, and the like) are often stimulated by hydraulic fracturing treatments. In traditional hydraulic fracturing treatments, a treatment fluid, sometimes called a carrier fluid in cases where the treatment fluid carries particulates entrained therein, is pumped into a portion of a subterranean formation (which may also be referred to herein simply as a “formation”) above a fracture gradient sufficient to break down the formation and create one or more fractures therein. The term “treatment fluid,” as used herein, refers generally to any fluid that may be used in a subterranean application in conjunction with a desired function and/or for a desired purpose. The term “treatment fluid” does not imply any particular action by the fluid or any component thereof. As used herein, the term “fracture gradient” refers to a pressure (e.g., flow rate) necessary to create or enhance at least one fracture in a subterranean formation.
Typically, particulate solids, such as graded sand, are suspended in a portion of the treatment fluid and then deposited into the fractures. The particulate solids, known as “proppant particulates” or simply “proppant” serve to prevent the fractures from fully closing once the hydraulic pressure is removed. By keeping the fractures from fully closing, the proppant particulates form a proppant pack having interstitial spaces that act as conductive paths through which fluids produced from the formation may flow. The term “proppant pack” generally refers to a collection of proppant particulates in a fracture. The degree of success of a stimulation operation depends, at least in part, upon the ability of the proppant pack to permit the flow of fluids through the interconnected interstitial spaces between proppant particulates.
One technique to increase the conductivity of a fracture involves placing a much reduced volume of proppants in a fracture in order to create a high porosity fracture. In such operations, the proppant particulates within the fracture may be widely spaced but still present in an amount sufficient to hold the fracture open and allow for production fluids to flow. An increased fracture conductivity may result due to the fact that the produced fluids may flow around widely spaced proppant rather than through the relatively small interstitial spaces in a proppant pack.
Proppant settling may occur when forming such proppant packs or widely spaced proppant particulates within a fracture. Low-viscosity fluids may be particularly susceptible to such settling, where proppant particulates settle out and quickly form a dune at a bottom portion of a fracture. Once such settling occurs, an arch may be formed on top of the fracture bed that does not comprise proppant due to fracture closure stresses.